A filter is a filtering means used in apparatuses such as a water purifier and an ionizer, which produce functional water. As water pollution becomes severe, interest in the standard of cleanliness of drinking water and residential water is increasing. According to this situation, the demand for water purifiers comprising filters therein is dramatically increasing, and there are a lot of general users in homes and restaurants, in which such water purifiers are used.
The filters used in such water purifiers must be periodically replaced with new ones, but the replacement of the filters must generally be carried out by specialists trained by manufacturers of the water purifiers, because the filters are installed inside the water purifiers in a manner such that it is difficult for general users to replace the filters.
Even if a user tries to replace the filter himself or herself, since the filter is generally securely assembled and consists of a plurality of parts having a complex structure, it is difficult for an ordinary person to replace the filter without technical knowledge. Accordingly, this places an additional burden on manufacturers as well as users every time the users replace the filters.
Further, since a plurality of parts is needed to assemble the filter having the complex structure, raw material costs for preparing individual parts are incurred, which results in the increase of the manufacturing cost and the user's cost for the use of the water purifier. In particular, since a water purifier needs a plurality of filters, instead of using only a single filter, cost and labor for replacing the filters in the water purifier impose a heavy burden on users.